Substitute for hard paper, ebonite, fiber, and the like and alpha process for manufacturing the same



Patented June 24, 1930 UNITED STATES PATENT OFFICE HANS FRIEDLANDER, OF BERLIN-WILMERSDORF, AND ARTHUR JANSER, OIE- BERLIN- CHABLOTTENIBURG, GERMANY; SAID J AN SER ASSIGNOR TO SAID FRIEDLANDER SUBSTITUTE FOR HARD PAPER, EBONITE, FIBER, AND THE LIKE AND A PROCESS FOR MANUFACTURING- THE SAME No Drawing. Application filed June 24, 1925, Serial No. 39,376, and in Austria June 26, 1924.

This invention relates to fibrous materials I wise disseminated therethrough and fully saturating the materials; it further comprises the process in which such fibrous materials are saturated with hardened Montan wax.

In our process, we advantageously impregnate fibrous materials such as cardboard, felt, paper-mach, etc., with hardened Montan wax, in the molten state, impregnation being continued until the fibrous material is substantially saturated and aided, if desired, by the use of pressure or vacuum.

After cooling, which may take place under pressure, there is obtained an elastic material of sounding hardness, high tensile, compressive and bending strength, with high insulating capacities, which may be easily worked, capable of replacing for many technical purposes the well known technical materials such as ebonite, hard paper and fiber. This is all the more remarkable, as the primary materials, e. g. cardboard and hardened Montan wax, cannot be expected to produce such an effect by themselves, since neither the wax nor the fibrous material possesses one of the'qualities specified: card-' board being pliable and of low strength and on the contrary hardened Montan wax being very brittle and exempt of any breaking strength.

This exceptional increase of the properties referred to may be ex lained by the cryptocristalline structure 0 the hardened Montan wax.

It is essential in accordance with the invention that not Montan wax in its original state is used but Montan wax which has been hardened by the addition of small quantities of resins, metallic salts, highmolecular weight acids and the like, or by heatingthe Montan wax, before or during the impregnation operation, to 200 C. or more. Methods of hardening soft waxes are well known.

The impregnation itself is facilitated and its duration shortened when the fibrous materials treated already contain a part of the hardened Montan wax necessary to completely fill up the pores in a powdered condition or precipitated as a so called waxsizing.

In this state the materials of course show none of the properties specified according to the idea of the present invention, since the wax particles are dispersed without any coherence between the fibers and are melted together with the molten hardened Montan wax but under the influence of the same during impregnation.

For the impregnation materials of any description and shape made of any fibrous material, such as cardboard, felt, papiermach pieces, which, manufactured in any known way, may also contain mineral loading materials, binding materials, &c., are suitable.

A material of specific properties is obtained by the impregnation of materials glued together (lined) to form plates, tubes, &c., inseveral layers by means of suitable agglutinants such as casein and water glass. Objects manufactured in this way afford an especially high cracking, breaking or blending resistance.

The materials may also undergo, prior to impregnation with hard waxes, a preliminary treatment (preliminary impregnation) with other substances which only partially fill up the pores of the primary material leaving the same partially open for the wax impregnation proper. Hereby the technical properties of the finished materials, e g. their hardness and strength, in general the .mechanical qualities, may be considerably improved.

Compact materials, e. g. highly sized an pressed cardboards are not fit for double impregnation, but for simple wax treatment. A material especially suited for double impregnation is cotton felt as used for filtering.

For the purpose of preliminary impregnation there may be used dissolved or liquid natural or artificial resins, e. g. bakelite or other substance such as impregnating varnishes, water glass orthe like; amongst these stuffs there may be chosen such ones having a hardening efiect upon the hard wax used in the second impregnation.

The double impregnation affords materials or bodies consisting of three phases or.

substances or systems completely penetrating each other. This fact may scientifically explain the-good mechanical properties of the products obtained.

In consequence of the preliminary impregnation the fibers of the fundamental material are protected against heat in the subsequent impregnation so that with the second impregnation with hardened Montan wax the temperature may be increased.

Examples 1. Dry' cardboard sized with aluminum resinate in a known way is immersed in melted Montan wax at a temperature which is raised from to 230 centigrade and left in the bath until it is completely saturated. Then the plates are allowed to cool with or without pressure applied to.

2. Papier-mach pulp prepared in a known way is mixed with powdered Montan wax and formed into a desired shape. When solidified these articles are treated with melted Montan wax heated to a high temperature as described in the preceding example.

3. Cotton felt,- e. g. .in slabs as used for filters is saturated with a solution of artificial resin in a solvent, e. g. a 410% solution of bakelite, and then dried. The ma terial impregnated in this way is hardened .at centigrade in the known way and finally immersed in melted Montan wax heated to a temperature of 230 C. and further treated according to Example 1.

What we claim is: The process of preparing hard sheet material which comprises impregnating felted fibrous material with Montan Wax heated to above 200 ;C.

In testimon whereof we have signed our names to thisl specification.

HANS FRIEDLANDER. ARTHUR J ANSER. 

